Waste Management aqua plus combines the know-how and areas of competence of its parent companies. In the area of waste management, this is especially the City of Vienna. Vienna has long been disposing of sewage sludge safely through incineration or humification without using valuable landfill space. aqua plus is a competent partner for waste management projects, especially for sewage sludge disposal problems and landfill restoration projects. The combination of landfill restoration and sewage sludge humification offers many operational advantages.